Tim Walz and JD Vance have faced off in their one and only US vice ...

It's a common adage in US politics that vice-presidential debates don't matter all that much.

But the debate between Republican VP nominee JD Vance and Democrat Tim Walz was, if nothing else, eagerly anticipated.

In an election that has so far featured two assassination attempts, a reshuffle of the Democratic ticket, and achingly close polling, the stakes of the running mate face-off felt higher than usual. 

During the 90-minute debate broadcast from New York City, the contrast between Walz and Vance in style, personality and political philosophy was on full display.

While Vance, a 40-year-old Ohio senator, has only been in politics for 18 months, he is an experienced live performer thanks to his repeated appearance on Fox News. 

Polls show he is also deeply unpopular with many Americans.

Walz, Minnesota's Democratic Governor, has had a longer political career, but is known for being a folksy, off-the-cuff communicator.

He is more popular with voters than Vance, thanks in part to efforts by Democratic strategists to cast him as the internet's favourite dad.

From big questions about the future of the Middle East to the fate of the US economy, these were the key moments from the vice-presidential debate.

The Middle East was the first item on the agenda 

The first question of the debate was about the Middle East.

Earlier today, Iran fired about 200 missiles at Israel in response to the killings of senior leaders of Hamas, Hezbollah and Iran's Revolutionary Guard.

The candidates were asked if they would support a pre-emptive strike by Israel on Iran.

Walz, who appeared a little nervous in the first moments of the debate, used his answer to criticise Republican nominee Donald Trump, saying that "steady leadership" is fundamental during a time of global upheaval.

"The world saw on the debate stage a few weeks ago a nearly 80-year-old Donald Trump talking about crowd sizes and it is not what we need at the moment," he said.

"It is not just that — those closer to Donald Trump understand how dangerous he is when the world is this dangerous. His chief of staff John Kelly said he was the most flawed human being he had ever met." 

Vance, meanwhile, appeared more polished in his first answer, taking a moment to thank viewers for "caring enough about this country" to tune into the debate.

He then said it would be up to Israel to do what they need to do to keep their country safe.

"We should support our allies wherever they are when they're fighting the bad guys," he said.

The debate got awkward as Vance and Walz were asked to explain historic comments

A few months ago, Vance and Walz were not well known political figures. But since being catapulted onto the national stage, journalists have been digging into their past comments, which made for some awkward moments during the debate.

JD Vance (left) and Tim Walz shook hands when they met for the first time on the debate stage.  (Reuters: Brendan McDermid )

The moderators asked Walz to explain why he previously claimed to be in Hong Kong during the Tiananmen Square massacre of June 1989, when records show he didn't arrive in the region until August of that year.

Walz said he misspoke.

"I will be the first to tell you, I have poured my heart out to my community and tried to be the best I can and I have not always been perfect," he said.

"I am a knucklehead at times."

The moderators then asked Vance to explain why he is Trump's running mate when he described him as "America's Hitler" in 2016.

"I have been extremely open about the fact that I was wrong about Donald Trump," he said.

"When you screw up and speak, and you change your mind, you ought to be honest with the American people."

The climate change question 

Hurricane Helene has caused widespread flooding and damage in Florida, Georgia, South Carolina, North Carolina, Virginia and Tennessee.

Hurricane Helene's death toll has surpassed 150 as rescuers search for survivors across several southern US states.  (Reuters: Marco Bello)

The death toll currently stands at 150, and may rise.

When asked what responsibility a Trump administration would have to reduce the impact of climate change, Vance said the hurricane is an "unbelievable, unspeakable human tragedy".

"Climate change is a very important issue. People are worried about crazy weather patterns but it is important for us to firstly say, Donald Trump and I support clean air and clean water," he said.

Walz noted that Trump previously described climate change as a "hoax".

He said that farmers in his home state of Minnesota "know climate change is real", and are experiencing "back to back" droughts and floods.

"The solution for us is to continue to move forward, [to acknowledge] that climate change is real," he said.

"Reducing our impact is absolutely critical but this is not a false choice. You can do that at the same time you're creating jobs as we are seeing all across the country."

Both Vance and Walz try to appeal to American women

The debate got tense when the moderators brought up abortion access.

In 2022, the US Supreme Court overturned Americans' constitutional right to terminate a pregnancy, and sent the issue back to the states to decide.

Polls suggest this is pushing more women to consider voting for Democratic candidates over the Republican party.

Vance has caused controversy with his anti-abortion statements in the past — in 2022, he said he "'would like abortion to be illegal nationally."

On the debate stage, Vance denied ever backing a national abortion ban, and said he and Trump want to be "pro-family in the fullest sense of the word".

"We've got to do so much better a job at earning Americans' trust back," he said.

Walz said that the Republican party wants to make it more difficult for Americans to get contraception and limit access to infertility treatment.

"We made sure that we put women in charge of their health care," he said.

"This is a basic human right."

The economy will decide the winner of this race 

Despite the threat of war and natural disasters, the US election will likely be decided on economic issues.

Inflation and cost of living remains the top concern for voters, according to most US polls.

Trump long held an advantage among polled US voters, who said they trusted his ability to handle economic issues over Democrats.

But the gap between Trump and Democratic nominee Kamala Harris is starting to narrow, according to recent polls.

That might be due to easing inflation and the Federal Reserve cutting interest rates, or it might be that voters are getting to know Harris better.

Walz was asked about Harris's campaign pledge to give $US25,000 ($36,000) payments to first-time homebuyers and build 3 million new homes to help ease the pressure.

"We need to make it more affordable," he said.

"People with stable housing end up with stable jobs. People with stable housing have their kids able to get to school. All of those things in the long run, end up saving our money."

In response, Vance said that "unused" federal land should be used for new housing.

"We have a lot of Americans that need homes. We should be kicking out illegal immigrants who are competing for those homes, and we should be building more homes for the American citizens who deserve to be here," the Republican said.

Will the VP debate change minds? 

The debate ended with a rather tense back-and-forth about Trump's refusal to accept that he lost the 2020 election.

Vance repeatedly declined to answer a question from Walz about whether Trump lost four years ago, instead trying to shift the conversation back to censorship. 

"That is a damning non-answer," Walz said. 

"When this is over, we need to shake hands this election, and the winner needs to be the winner. This has got to stop. It’s tearing our country apart." 

Historically, vice-presidential debates don't have much impact on the outcome of US elections.  (Reuters: Caitlin Ochs)

Vance did say he would concede the election if he loses on November 5. 

"If Tim Walz is the next vice-president, he will have my prayers and best wishes and my help whenever he wants it," he said. 

The debate then ended with candidates shaking hands and introducing each other to their wives — a much more conciliatory mood than the debate between Harris and Trump last month. 

Aggregates of national polls suggest this race is in a dead heat.

Nate Cohn, the New York Times' polling expert, says if polls are correct, "it would be the closest modern US presidential election".

Could the vice-presidential debate shift the needle on election day on November 5? 

Stranger things have happened in 2024.